gecko-dev/dom/media/mediacontrol/AudioFocusManager.h

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C++

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef DOM_MEDIA_MEDIACONTROL_AUDIOFOCUSMANAGER_H_
#define DOM_MEDIA_MEDIACONTROL_AUDIOFOCUSMANAGER_H_
#include "base/basictypes.h"
#include "nsTArray.h"
#include "VideoUtils.h"
namespace mozilla {
namespace dom {
class IMediaController;
class MediaControlService;
/**
* AudioFocusManager is used to assign the audio focus to different requester
* and decide which requester can own audio focus when audio competing happens.
* When the audio competing happens, the last request would be a winner who can
* still own the audio focus, and all the other requesters would lose the audio
* focus. Now MediaController is the onlt requester, it would request the audio
* focus when it becomes audible and revoke the audio focus when the controller
* is no longer active.
*/
class AudioFocusManager {
public:
void RequestAudioFocus(IMediaController* aController);
void RevokeAudioFocus(IMediaController* aController);
explicit AudioFocusManager() = default;
~AudioFocusManager();
uint32_t GetAudioFocusNums() const;
private:
friend class MediaControlService;
// Return true if we manage audio focus by clearing other controllers owning
// audio focus before assigning audio focus to the new controller.
bool ClearFocusControllersIfNeeded();
void CreateTimerForUpdatingTelemetry();
// This would check if user has managed audio focus by themselves and update
// the result to telemetry. This method should only be called from timer.
void UpdateTelemetryDataFromTimer(uint32_t aPrevFocusNum,
uint64_t aPrevActiveControllerNum);
nsTArray<RefPtr<IMediaController>> mOwningFocusControllers;
RefPtr<SimpleTimer> mTelemetryTimer;
};
} // namespace dom
} // namespace mozilla
#endif // DOM_MEDIA_MEDIACONTROL_AUDIOFOCUSMANAGER_H_